August 10, 2016

Yesterday, my Great Courses DVDs and guidebook "The Nature of Earth: An Introduction to Geology" arrived from Amazon. I watched the first disc today - six lessons. Heaven! Well, Earth! I should have purchased and watched it before I began my travels through the Ring of Fire, but it didn't occur to me to see if Great Courses had a geology course. I have been looking for one on Coursera for two years but to no avail. My goal is to be able to look at minerals and rocks and know what they are. I now know that the lava at Craters of the Moon is basaltic, that magma and lava are the same thing (below and above the surface of the Earth, respectively), that granitic magma has the highest viscosity, and that andesitic magma is only found in ocean trenches. I also know that a mineral must be: naturally occurring, a solid, inorganic, and, have defined chemical composition and crystalline structure. I know that there are two types of minerals: silicates and non-silicates. Silicates are either ferromagnetic (contain iron and magnesium) or not, and that they have five different tetrahedral crystalline structures. I haven't learned about non-silicates yet. I can't wait!